Creating a small privacy screen with urban planter boxes is a fantastic way to add greenery and seclusion to your balcony, patio, or deck. The number of boxes you'll need isn't one-size-fits-all; it depends on several key factors.
First, measure the length of the area you want to screen. A standard rectangular planter box is often about 24 to 36 inches long. For a basic screen, planter boxes should be placed side-by-side with little to no gap between them for immediate coverage. Therefore, simply divide your total screen length by the length of one box. For a 10-foot (120-inch) wall, you would need approximately 4 boxes that are 30 inches long each.
However, if you're using plants that will bush out or climb, like arborvitae, bamboo, or climbing jasmine, you can space the boxes 6 to 12 inches apart. The mature width of the plants will fill the gaps, allowing you to use fewer boxes. In this case, for a 10-foot span with plants that spread 2 feet wide, you might only need 3 or 4 boxes strategically spaced.
Consider height for true privacy. Boxes 18-24 inches tall provide a good base for plants to grow into a screen at least 5-6 feet high. Always use large, sturdy boxes with proper drainage and fill them with quality soil to support healthy, dense growth. Start with a simple layout, and remember, your green screen will become more effective as your plants mature and fill in.